A sapper, also called pioneer or combat engineer, is a combatant or soldier who performs a variety of military engineering duties such as breaching, demolitions, bridge-building, laying or clearing minefields, field defenses as well as building, road and airfield construction and repair.
https://en.wikipedia.org/wiki/Sapper

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IN the US, such work is performed by the US Army Corps of Engineers:

The United States Army Corps of Engineers (USACE),[5] also sometimes shortened to CoE[6] is a U.S. federal agency under the Department of Defense and a major Army command made up of some 37,000 civilian and military personnel,[1] making it one of the world's largest public engineering, design, and construction management agencies. Although generally associated with dams, canals and flood protection in the United States, USACE is involved in a wide range of public works throughout the world. The Corps of Engineers provides outdoor recreation opportunities to the public, and provides 24% of U.S. hydropower capacity.
https://en.wikipedia.org/wiki/United_States_Army_Corps_of_En...